| With the development of the semiconductor and power electronic technology, power electronic devices are applying widely in every area relating to industry. As a very important section of the whole system, the reliability of power electronic devices dicides whether the system could operate steadily. For this reason, the research of fault diagnosis for power electronic system is necessary for reducing the fault and raising the safety of the system.At present, complex network is widely applying in the areas of social sciences, computer network, bio-science and power system. A lot of real systems are proved to be small-world network and scale-free network, small-world theory and scale-free theory is become effective tools to analyse the characteristic of the network. So in order to realize the fault diagnosis, fragility analysis and stability of power electronic system, the power electronic system can be researched from the network characteristic by complex network theory. This paper sets up the network model of power electronic system first, and analyses the network characteristic, and then the changes of network characteristic are researched when fault happens. At last, the importance of nods is estimated by analyzing the connectedness of oriented graph.The main substances of this paper include:1. Two network models of power electronic system are builded, and finally adopt the model of breaking common ground elements as analyzing object by comparing their influence to network characteristic. And then a calculation software which could connect with Protel is designed, and the network parameters of some power electronic systems are calculated by this software. At last, the power electronic system is proved to be provided with small-world character and scale-free character.2. The network models of short circuit and broken circuit are builded to analyse the influence to the network characteristic of nodes, when one of which is in trouble. By analyzing some real power electronic system with a fault analyzing software, the theory reduction is proved perfectly correct.3. The scale-free character of power electronic system is researched, and the oriented graph model is builede. The importance of nodes is estimated by analyzing their influences to the connectedness of the whole network. |
